A farmer has delighted conservationists by discovering a community of rare birds in the Sussex countryside.

The RSPB had called for farmers to help save tree sparrows from extinction by reporting any sightings on or near their land.

Now a previously-unrecorded colony of the birds, among the fastest-declining in the UK, has been uncovered in the Weald east of Haywards Heath.

Before the discovery, there were just two known breeding areas left in the whole of Sussex, both on its eastern fringes.

The exact location of all three colonies will remain a secret because the rarity of the breed has made them a target for egg collectors.

Tree sparrows are similar to house sparrows but can be easily identified by their all-chestnut coloured head (the house sparrow's crown is grey) and by a black spot in the middle of their pure white cheeks.

They nest in holes, traditionally in old trees, hedges or farm buildings but are increasingly restricted to damp places such as near reservoirs.

Andy Cotton, organiser of the RSPB survey Where Are They Now?, which asked for farmers' help, said: "We are delighted to find out about this colony.

"Tree sparrows are birds of the farmed landscape, which is why we turned to the very people who know farmland best to find them - farmers."

RSPB spokesman Adrian Thomas said: "To find a site that is quite a long way from other known sites was quite a breakthrough.

"Somebody who had picked up the survey form we sent out with the agricultural Press called us to tell us they had spotted one of the birds. I believe it was the landowner of where the colony is situated.

"The colony consists of a small number of pairs of birds, which these days is extremely rare."

The RSPB will work with the landowner to ensure the colony is allowed to thrive.

But the charity is disappointed the survey only turned up three new breeding sites across the South-East.

Mr Cotton said: "It all goes to show the perilous state tree sparrows are in.

"It is astonishing to think that in the Seventies flocks of 500 were still being recorded on the Downs."

The UK population of the bird declined by 95 per cent between 1970 and 1998, probably because fewer seed and insect food sources were available on farmland.

The RSPB is joining forces with the Farming and Wildlife Advisory Group to advise farmers on how they can help the breed.

Leaflets are available by calling 01273 775333.

Sightings can be reported by calling the same number or by emailing andy.cotton@rspb.org.uk